I'm experiencing an odd problem with my desktop, which I'm unable to find any solutions (or reproduces) on the web, partly because for any search terms I can think of, I come up with a lot of hits that don't relate to my problem...
The problem I'm seeing is that the desktop "freezes", so that what was shown on the desktop before is "left there" until something else is placed on top of it. I realize this explanation isn't perfect, so please see the screenshot below.
I'm running Ubuntu 11.04 on an ASUS N53, and have followed most of the advice here, but without success. I don't even know where to start troubleshooting.